The present invention relates generally to welding systems and, more particularly, to a welding power supply housing assembly having a wind tunnel therein.
Welding power supply housings have a front panel which includes an on/off switch as well as controls such as power adjustment dials and output gauges. Additionally, the housing includes a rear panel and a cover panel. Such welding power supply housings must understandably enclose the entirety of the electrical components.
The housing, being fully enclosed, restricts natural convection cooling of the electronic components required to transform input energy into a desired form. Therefore, louvers are typically constructed into the front and rear panels to accommodate air flow through the housing. Fans have often been incorporated into the assembly of the welding power supply to facilitate improved cooling of the electrical components. Such air flow creates the additional problem of introducing heavy particulate flow into the interior of the housing. These particulates can build up on various components and can effectively shorten the life of certain electrical components of the power supply.
The electrical components can be classified into four general categories. The first category of component includes components that are preferably not physically attached to a circuit board and preferably not exposed to a cooling flow. Components would qualify for this category if, due to the size of the component, it would be impractical to physically attach the components to a circuit board and the component is adequately cooled by natural convection. The second category of components includes components that are preferably attached to the circuit board but are also preferably not exposed to a cooling flow. These components are physically attached to a circuit board of the power supply and cooled by a heat sink. The heat sink is also physically attached to the circuit board. The third category of components includes components that are preferably exposed to a cooling flow but preferably not physically attached to the circuit board. These components are those components that are also impractical to physically attach to the circuit board and also require more cooling than natural convection can provide. These components are also durable enough to withstand the particulates that are carried in the cooling flow. The fourth category of components includes components that are preferably exposed to the cooling flow and attached to the circuit board. These components are those components that can withstand the particulates carried in the cooling flow but, because of their size, can be attached to the circuit board.
Early cooling methods allowed for a cooling flow to follow a tortuous path through the entire power supply housing. Although this improved the cooling of the electrical components, it did not address the problem of particulate accumulation to certain electrical components because there was no separation between the cooling flow and the electrical components. Other methods of cooling the electrical components allow for isolation of preferred electrical components from the cooling flow. However, these methods increase the complexity of the assembly of the power supply and hinder assembly by preventing assembly of the electrical components of the power supply prior to installation of the electrical assembly within the power supply housing.
The method of electrical connectivity is another consideration of the present invention. There are several methods of connecting electrical components to circuit boards. These methods include hand soldering, mechanical connectors, and wave soldering, to name a few. Of these methods, the most preferable method of connecting the electrical components to the circuit board is by wave soldering. This method yields a higher quality connection between the component and the circuit board compared to hand soldering and mechanical connections.
Power supply assemblies that do separate certain electrical components from the cooling flow utilize partitioning of the housing. These systems connect the electrical components that can withstand being placed in a polluted cooling flow and heat sinks to one side of a partition and then connect the circuit board to the other side of the partition. The components mounted to the opposite side of the partition must then be electrically connected to the circuit board. This process of partitioning adds to both assembly time and cost. Additionally, these secondary electrical connections are often made by either hand soldering or using a mechanical means to make the connection because such an assembly is not conducive to wave soldering. These assemblies also do not provide for the fourth category of electrical components as discussed above. As such, components that are preferably exposed to the cooling flow must be attached to the housing and then electrically connected to the circuit board.
Therefore, it would be desirable to design a system and method capable of separating the electrical components into those that are preferred to be located in a cooling flow from those that are preferred to be located outside a cooling flow while also simplifying the assembly processes. Additionally, it would be desirable to have a system that allows for near completion of the electrical assembly prior to installation of the electrical assembly within the housing.